1. Field of the Invention
This invention relates to a data recording apparatus, and more particularly, to a data recording apparatus capable of recording plural kinds of digital information signals having different bit rates from one another.
2. Description of the Prior Art
Recently, high speed processing in digital transmission techniques has been advancing, and transmission of digital signals at bit rates not less than 100 Mbps has become possible. Various kinds of transmitters and transmission media which perform transmission at such high bit rates have also been announced. Furthermore, data recorders for recording these digital signals having high bit rates are being developed.
Data transmission at such high bit rates finds wide applications, and various kinds of transmission bit rates are also provided. Even when the main information to be transmitted is limited to the so-called high-definition television signals, various transmission bit rates can be considered depending on band compression techniques, handling of voice signals and amount of other information to be transmitted.
Heretofore, it has been common to provide data recording apparatuses each of which is exclusively used for each bit rate, when these digital signals having various transmission bit rates are recorded. Even when it is considered to utilize an identical mechanism for recording data having different bit rates, it has been necessary to separately provide clock frequencies, recording formats and the like when recording. Consequently, the apparatus itself has plural channels of signal processing units. This is not preferable because one apparatus becomes large in size especially when several kinds of digital signals are to be recorded.
Now, it can be easily imagined that plural channels of digital signals having low bit rates can be recorded using such data recorders having a high bit rate.
In conventional data recorders, however, the fact is that recording can be performed only for a predetermined number of channels and at a predetermined bit rate, not that recording of an arbitrary number of channels can be performed for several digital signals having various bit rates. Hence, the conventional data recorders can be used for only limited applications.